Adolescent Trajectories Research Articles

Cigarette Smoking Trajectories in Adolescent Smokers: Does the Time Axis Metric Matter?

Most studies modeling adolescent cigarette smoking trajectories use age as the time axis, possibly obscuring depiction of the natural course of cigarette smoking. We used a simulated example and real data to contrast smoking trajectories obtained from models that used time since smoking onset or calendar time (age) as the time axis. Data were drawn from a longitudinal investigation of 1293 grade 7 students (mean age 12.8 years) recruited from 10 high schools in Montreal, Canada in 1999-2000, who were followed into young adulthood. Cigarette consumption was measured every 3 months during high school, and again at mean ages 20.4 and 24.0. Analyses using time since onset of smoking as the time metric was restricted to 307 incident smokers; analysis using calendar time included 645 prevalent and incident smokers. Smoking status and nicotine dependence (ND) were assessed at mean ages 20.4 and 24.0. Simulated data mimicked the real study during high school. Use of different time metrics resulted in different numbers and shapes of trajectories in the simulated and real datasets. Participants in the calendar time analyses reported more ND in young adulthood, reflecting inclusion of 388 prevalent smokers who had smoked for longer durations. Choosing the right time metric for trajectory analysis should be balanced against research intent. Trajectory analyses using the time since onset metric depict the natural course of smoking in incident smokers. Those using calendar time offer a snapshot of smoking across ages during a given time period. This study uses simulated and real data to show that trajectory analyses of cigarette smoking that use calendar time (e.g., age) versus time since onset as the time axis metric tell a different story. Trajectory analyses using the time since onset metric depict the natural course of smoking in incident smokers. Those using calendar time offer a snapshot of smoking across ages during a given time period. Choosing the right time metric should be balanced against research intent.

Growth dynamics among adolescent girls in Bangladesh: Evidence from nationally representative data spanning 2011-2014.

BackgroundAdolescence is the last opportunity to reverse any growth faltering accumulated from fetal life through childhood and it is considered a crucial period to optimize human development. In Bangladesh, a growing double burden of underweight and obesity in adolescents is recognized, yet limited data exists on how, when, and where to intervene. This study assesses the dynamics of growth among adolescent girls in Bangladesh, providing insight about critical junctures where faltering occurs and where immediate interventions are warranted.MethodsWe pooled data from Bangladesh’s Food Security and Nutrition Surveillance Project collected between 2011 and 2014 to document the age dynamics of weight and linear growth. 20,572 adolescent girls were measured for height and 19,345 for weight. We constructed growth curves for height, weight, stunting, and underweight. We also stratified growth dynamics by wealth quintile to assess socioeconomic inequities in adolescent trajectories.ResultsHeight-for-age z-score (HAZ) in Bangladeshi girls deteriorates throughout adolescence and especially during the early years. Mean HAZ decreases by 0.20 standard deviations (sd) per year in early adolescence (10–14 years) vs 0.06 sd/year during late adolescence (15–19 years), while stunting increases by 16 percentage points (pp) vs 6.7 pp, respectively. Conversely, BMI-for-age z-score (BAZ) increases by 0.13 sd/year in early adolescence vs 0.02 sd/year in late adolescence, and underweight decreases by 12.8 pp vs 3.2 pp. Adolescent girls in all socioeconomic groups show a similar pattern of HAZ and BAZ dynamics, but the curve for the richest quintile stays above that of the poorest across all ages.ConclusionsTrends and levels of stunting and underweight among adolescent girls in Bangladesh are worrisome, suggesting substantial linear growth faltering in early adolescence, with improving weight-for-age occurring only as linear growth slows and stops. Given the rising burden of non-communicable diseases (NCDs) in Bangladesh and emerging evidence of the link between stunting and later chronic diseases, greater attention to adolescent growth and development is needed. Our findings suggest that, to address stunting, interventions in early adolescence would have the greatest benefits. School-based interventions could be a way to target this population.

Impact of stress and parenting on respiratory sinus arrythmia trajectories in early adolescence.

The effects of stress and parenting on 1-year trajectories of physiological emotion regulation capacity among adolescents were examined. Consistent with the vulnerability-stress and allostatic load models, stress (chronic family and marital) was hypothesized to be associated with less favorable trajectories of basal respiratory sinus arrhythmia (RSA) over 1 year. This relationship was further hypothesized to be moderated by parenting practices (warmth, neglect, and rejection) and adolescent sex. Participants included 150 adolescents (51.3% female), 11-15 years of age (M=13.04, SD=0.89). Basal RSA and stress were assessed four times across 1 year. Results indicated a significant decrease in RSA over the course of 1 year (β=-0.15, p=.010). Warm parenting style was associated with lower RSA in environments of low marital stress and was also related with higher RSA in environments of high marital stress (β=0.86, p=.021). Rejecting parenting styles were associated with higher RSA in environments of low family stress and lower RSA in environments of high family stress (β=-0.60, p=.014). These findings may be explained by the Yerkes-Dodson law of optimal stress, suggesting that sufficient environmental challenge is needed to catalyze regulatory development.

Mental health, identity and informal education opportunities for adolescents with experience of living in state care: a role for digital storytelling

ABSTRACT The mental health difficulties and educational trajectories of adolescents with care-experience is a pervasive international concern. This article explores how digital technologies can facilitate self-reflective dialogues and informal education opportunities for adolescents with care-experience. Extracts from vlogs created during an ethnographic project working with adolescents (n = 10, six males and four females, M age = 15.3 years, age range: 14–18 years) and carers (n = 35, ages and gender not sought) in four English residential homes are thematically analysed. Three major themes were constructed: richness of everyday identity; complexities of in care identity; and renegotiating narrative traumas. Themes illustrated how engagement with a blended intervention (featuring digital and face-to-face elements) created opportunities for trusted adults to support the mental health, identity and educational needs of adolescents with care-experience. The paper concludes by critically discussing the educational implications for those working with this group.

Posttraumatic stress disorder and growth: Examination of joint trajectories in children and adolescents

Positive health endpoints are not the opposite of negative endpoints. Previous studies examining posttraumatic stress disorders (PTSD) and posttraumatic growth (PTG) trajectories have overlooked the co-existence of PTSD and PTG, making it difficult to accurately distinguish individuals with various posttraumatic presentations, causing the effects of targeted interventions to be discounted. To fill this gap, the current study sought to examine joint PTSD and PTG trajectories in children and adolescents. Eight hundred and seventy-six Chinese children and adolescents were recruited to complete self-report questionnaires 6, 12, and 18 months after the Ya'an earthquake. Multiple-process growth mixture modeling analysis was used to test the study proposal. Five distinct joint PTSD and PTG trajectory types were found: recovery, growth, struggling, resistant, and delayed symptoms. Female students and students who felt trapped or fearful were more likely to be in the struggling group, and students who experienced injury to themselves or family members were more likely to belong to the delayed symptom group. These findings suggest that postdisaster psychological services should be provided to relieve delayed symptoms in individuals who experience injury to themselves or their family members, and individuals in the struggling group should be supported to achieve growth.

The Greater Houston Area Bipolar Registry-Clinical and Neurobiological Trajectories of Children and Adolescents With Bipolar Disorders and High-Risk Unaffected Offspring.

The aims of this article are to discuss the rationale, design, and procedures of the Greater Houston Area Bipolar Registry (HBR), which aims at contributing to the effort involved in the investigation of neurobiological mechanisms underlying bipolar disorder (BD) as well as to identify clinical and neurobiological markers able to predict BD clinical course. The article will also briefly discuss examples of other initiatives that have made fundamental contributions to the field. This will be a longitudinal study with participants aged 6–17 at the time of enrollment. Participants will be required to meet diagnostic criteria for BD, or to be offspring of a parent with BD. We will also enroll healthy controls. Besides clinical information, which includes neurocognitive performance, participants will be asked to provide blood and saliva samples as well as to perform neuroimaging exams at baseline and follow-ups. Several studies point to the existence of genetic, inflammatory, and brain imaging alterations between individuals at higher genetic risk for BD compared with healthy controls. Longitudinal designs have shown high conversion rates to BD among high-risk offspring, with attempts to identify clinical predictors of disease onset, as well as clarifying the burden associated with environmental stressors. The HBR will help in the worldwide effort investigating the clinical course and neurobiological mechanisms of affected and high-risk children and adolescents with BD.

Patterns and Predictors of Different Youth Responses to Attachment-Based Parent Intervention

ABSTRACT Objective Few studies have evaluated attachment-based parent interventions for pre-teens and teens, and in particular, differential adolescent trajectories of response. This study examined distinct patterns, and multi-level predictors, of intervention response among youth with serious behavioral and mental health problems whose parents participated in Connect, an attachment- and trauma-informed parent program. Method Participants included 682 parents (M age = 42.83, 86% mothers) and 487 youth (M age = 13.95, 53% female, 28.1% ethnic minority) enrolled in a community-based evaluation of Connect. Parents and youth reported on youth externalizing and internalizing problems (EXT and INT) at six time points from baseline through 18-months post-intervention. Demographic and youth and family level predictors were assessed at baseline. Results Growth mixture modeling revealed three distinct trajectory classes in both the parent and youth models based on different patterns of co-occurring EXT and INT and degree of improvement over time. Youth with severe EXT showed the largest and fastest improvement, and, interestingly, were characterized by higher callous-unemotional traits and risk-taking at program entry. Youth with comorbid EXT/INT demonstrated a partial or moderate response to intervention in the parent and youth model, respectively, and were characterized by more attachment anxiety at baseline. Most youth showed relatively moderate/low levels of EXT/INT at baseline which gradually improved. Caregiver strain also predicted trajectory classes. Conclusions These results have significance for tailoring and personalizing interventions for high-risk youth and provide new understanding regarding the profiles of subgroups of youth who show different responses to an attachment-based parent intervention.

Abstract MP44: Adolescent Predictors Of Changes In Weight Status From Adolescence To Adulthood: Evidence From The Addhealth Study

Introduction: The persistence of obesity from adolescent to adult ages is associated with risk of cardiovascular disease later in life. Data from cohorts that passed through childhood before 1980 show that when obesity is first observed in youth it often persists into adulthood. However, less is known about current weight trajectories of adolescents transitioning to adulthood. We examined the changes in weight status from adolescence to adulthood and baseline predictors of normal weight in adulthood. Methods: Study used data from the National Longitudinal Study of Adolescent Health (AddHealth) (n=14,135), a nationally representative sample of adolescents recruited in 1994 and followed up in 1996, 2001, and 2008. Weight and height measurements collected at each visit were used to classify weight status; we identified 4 trajectories between mean ages 16 and 30: 1) maintained normal weight, 2) achieved normal weight, 3) gained weight to enter the obesity category, and 4)maintained overweight or obesity. Logistic regression models included individual and family characteristics. Results: Among adolescents with normal weight, 56% gained weight to enter overweight or obesity categories 14 years later. Of those with overweight at baseline, 68% gained weight to enter obesity and 8% achieved normal weight; among adolescents with obesity, 89% maintained obesity, and only 2% achieved normal weight. After controlling for sex, age, race-ethnicity, and baseline weight status, adolescents who were trying to lose weight, skipped breakfast, ate dinner with their parents, had a mother with diabetes or obesity, a father with obesity, parents with less than high-school education, or married in high-school were less likely to have normal weight as adults. Independent of baseline weight status, adolescents who reported feeling loved were more likely to have normal weight in adulthood. Conclusion: Findings shed light on individual and family factors associated with normal weight outcomes after the transition from adolescence to adulthood.

Race/Ethnicity, Parental Support, and Youth Depressive Symptoms: A Moderated Longitudinal Mediation Analysis.

Racial/ethnic disparities in depression exist among youth in the United States. The purpose of this study was to determine if parental support trajectories in adolescence explain the relationship between race/ethnicity and depressive symptom trajectories in adulthood. A two-step longitudinal parallel process analysis with multigroup structural equation modeling was conducted with a nationally representative sample of youth (N = 5300; 48.5% female; M = 13.33 (Range:12-15) years at baseline). While parental support trajectories did not mediate the relationship between race/ethnicity and depressive symptoms, parental support trajectories were related to depressive symptom trajectories in adulthood. Immigrant generation status also moderated the relationship between race/ethnicity and depressive symptom trajectories. The results demonstrate the impact of parental support on later mental health outcomes regardless of race/ethnicity.

Depressive symptom trajectories and their gender differences in adolescents from multicultural families in South Korea: an ecological perspective

ABSTRACT This study examines the depressive symptom trajectories in middle-school adolescents from multicultural families in South Korea and explores their predictors from the ecological systems perspective. Using the latent growth model, we analysed a sample from the Multicultural Adolescents Panel Survey (2014–2016). Our findings revealed that depressive symptoms increased persistently with age. Girls presented a systematically higher risk of depressive symptoms than boys. Family support, two-parent families, parental monitoring, learning, friendships, positive perceptions about the residential area, and good health reduced depressive symptoms. Parental neglect, bullying, parental involvement in children’s grade, and acculturative stress increased depressive symptoms.

Transiciones y soportes. La familia y la comunidad en las trayectorias biográficas de adolescentes trans

Este artículo forma parte de una investigación en curso sobre la experiencia biográfica de la adolescencia trans. En él exploro el papel de la familia y la comunidad como soportes en las trayectorias de transición. Comprendo la adolescencia trans como un fenómeno sociocultural que regula las concepciones de edad y género, y en el que la experiencia de transición de los sujetos se da en el contexto sociohistórico sobre el que el sujeto decide y actúa. El Método Biográfico Narrativo Interpretativo me permite mostrar el papel de la familia y la comunidad como soportes en la trayectoria biográfica de transición de adolescentes trans, a partir de los siguientes temas: contarlo a la familia; la aceptación/rechazo familiar; y, cuando la familia rechaza, la comunidad sostiene. Para finalizar, en las conclusiones rastreo de qué manera actúan los soportes en el sentido y cuidado de sí de las personas adolescentes trans.

Air pollution and trajectories of adolescent conduct problems: the roles of ethnicity and racism; evidence from the DASH longitudinal study

PurposeNo known UK empirical research has investigated prospective associations between ambient air pollutants and conduct problems in adolescence. Ethnic minority children are disproportionately exposed to structural factors that could moderate any observed relationships. This prospective study examined whether exposure to PM2.5 and NO2 concentrations is associated with conduct problems in adolescence, and whether racism or ethnicity moderate such associations.MethodsLongitudinal associations between annual mean estimated PM2.5 and NO2 concentrations at the residential address and trajectories of conduct problems, and the potential influence of racism and ethnicity were examined school-based sample of 4775 participants (2002–2003 to 2005–2006) in London, using growth curve models.ResultsOverall, in the fully adjusted model, exposure to lower concentrations of PM2.5 and NO2 was associated with a decrease in conduct problems during adolescence, while exposure to higher concentrations was associated with a flattened trajectory of conduct symptoms. Racism amplified the effect of PM2.5 (β = 0.05 (95% CI 0.01 to 0.10, p < 0.01)) on adolescent trajectories of conduct problems over time. At higher concentrations of PM2.5, there was a divergence of trajectories of adolescent conduct problems between ethnic minority groups, with White British and Black Caribbean adolescents experiencing an increase in conduct problems over time.ConclusionThese findings suggest that the intersections between air pollution, ethnicity, and racism are important influences on the development of conduct problems in adolescence.

Correlates of Continuous Glucose Monitoring Use Trajectories in Children and Adolescents with Type 1 Diabetes.

The goal of this study was to characterize trajectories of continuous glucose monitoring (CGM) use in youth 5-12 weeks after starting CGM and examine what factors differentiate between the trajectory groups. Parent-youth dyads completed assessments before starting CGM. Days of CGM use between weeks 5 and 12 were accessed through cloud-based data repository. Three patterns of use were observed among 96 youth (mean age 13.4 ± 2.75 years; 75% white): sustained high, declining, and sustained low. Youth in the sustained low and declining groups were more likely than those in the sustained high group to use a receiver (versus smart phone). There were no differences between the trajectory groups with respect to age, race, ethnicity, income, or insulin regimen. Future research should examine trajectory groups for a longer follow-up period and identify baseline factors that reliably predict which youth will have low or declining CGM use over time.

Advancing our understanding of cognitive development and motor vehicle crash risk: A multiverse representation analysis

Neurobiological and cognitive maturational models are the dominant theoretical account of adolescents' risk-taking behavior. Both the protracted development of working memory (WM) through adolescence, as well as individual differences in WM capacity have been theorized to be related to risk-taking behavior, including reckless driving. In a cohort study of 84 adolescent drivers Walshe et al. (2019) found adolescents who crashed had an attenuated trajectory of WM growth compared to adolescent drivers who never reported being in a crash, but observed no difference in WM capacity at baseline. The objectives of this report were to attempt to replicate these associations and to evaluate their robustness using a hybrid multiverse – specification curve analysis approach, henceforth called multiverse representation analysis (MRA). The authors of the original report provided their data: 84 adolescent drivers with annual evaluations of WM and other risk factors from 2005 to 2013, and of driving experiences in 2015. The original analysis was implemented as described in the original report. An MRA approach was used to evaluate the robustness of the association between developmental trajectories of WM and adolescents’ risk-taking (indexed by motor vehicle crash involvement) to different reasonable methodological choices. We enumerated 6 reasonable choice points in data processing-analysis configurations: (1) model type: latent growth or multi-level regression, (2) treatment of WM data; (3) which waves are included; (4) covariate treatment; (5) how time is coded; and (6) link function/estimation method: weighted least squares means and variance estimation (WLSMV) with a linear link versus logistic regression with maximum likelihood estimation. This multiverse consists of 96 latent growth models and 18 multi-level regression models.

A multilevel analysis of the influence of bullying participant roles upon the trajectories of adolescents’ social and emotional competencies

This study analyzed how social and emotional competencies evolved according to adolescents’ involvement in bullying, and whether gender influenced social and emotional competencies’ development. Five-hundred-fourteen students ( Mage = 12.71; SD = 1.09) were assessed through self-reports at three different time points for one year. Results showed that students involved in the three analyzed bullying roles displayed a more negative trajectory in all but one social emotional competence analyzed compared to students not involved in bullying. The exception was students who bullied others for responsible decision making. Additionally, gender differences were only found in self-esteem trajectories; boys displayed a more pronounced decrease. In larger classes, students displayed higher levels of self-control, social awareness and responsible decision-making. These results showed that reduced social and emotional competencies were a consequence of bullying involvement for every bullying role analyzed.

Delinquency in Emerging Adulthood: Insights into Trajectories of Young Adults in a German Sample and Implications for Measuring Continuity of Offending

The majority of studies within the framework of Developmental and Life-Course Criminology focus on adolescence. There are even fewer studies that deal with heterotypic measures of delinquency. This study fills a gap in the literature by targeting exclusively the period of emerging adulthood (ages 18 to 28) and scrutinizing different trajectories and patterns of offending (offending portfolios) thereof. We discuss the topic of continuity of offending with changing opportunity structures for an adult population via contrast of one set of delinquent behaviors reflecting opportunity structures in adolescence (youth set) and one where adult-appropriate criminal activities were added (total set). We applied latent class growth analysis (LCGA) to both sets in a sample of 1810 German men and women aged 18 to 28 years. During emerging adulthood, average crime versatility and incidences increase slightly with items of the total set, while it decreases with only the youth set. LCGA on the total set reveals five meaningful trajectories with declining but also increasing slopes. Among these is one trajectory of innocuous adolescents, who start an offending career with mainly adult crimes during emerging adulthood. Of the sample, 45.25% reported at least one offense during that period. Traffic offenses and fraud are the most prevalent types of offending. While the sample’s majority is considered non-offenders, emerging adults do not entirely cease to commit offenses. Instead, they shift their preference towards age-appropriate and covert ways to act anti-socially. Trajectory groups reflect proclivities towards either youth, adult, or a mix of both types of crime.

Examining Trajectories of Early Adolescents’ Life Satisfaction in South Korea Using a Growth Mixture Model

Various aspects of early adolescence can have a key impact on adult life satisfaction. This study applied a growth mixture model to examine the trajectories of early adolescents’ life satisfaction and test the effects of individual (sex, subjective achievement, and self-esteem) and social factors (school adjustment and peer attachment) thereon. For this purpose, a growth mixture model was used on the fifth- (grade five), sixth- (grade six), and seventh- (grade seven) year panel data of 1917 grade one students from the Korean Children and Youth Panel Survey (2010–2016, National Youth Policy Institute), excluding missing samples. Participants were 990 boys (51.6%) and 927 girls (48.4%). The results indicated that the trajectories of life satisfaction could be categorized into three groups: “High Level-decreasing” (57.19%), “Moderate Level-stable” (37.62%), and “Low Level-increasing” (5.19%). Predictors for each class exhibited that female students and individuals with higher levels of self-esteem and school adjustment were more likely to be in the “Low Level-increasing” and “Moderate Level-stable” groups compared to male students and those reporting lower levels of self-esteem and school adjustment. Moreover, students with higher peer attachment were more likely to be in the “Low Level-increasing” group compared to the “High Level-decreasing” group. Educational implications to achieve positive life satisfaction by determining the influence of the predictors for each trajectory are outlined.

Trajectories of Depressive Symptoms among Multicultural Adolescents in Korea: Longitudinal Analysis Using Latent Class Growth Model.

The purpose of this study was to investigate the trajectory of depressive symptoms in multicultural adolescents using longitudinal data, and to identify predictive factors related to depressive symptoms of multicultural adolescents using latent class analysis. We used six time-point data derived from the 2012 to 2017 Multicultural Adolescents Panel Study (MAPS). Latent growth curve modeling was used to assess the overall features of depressive symptom trajectories in multicultural adolescents, and latent class growth modeling was used to determine the number and shape of trajectories. We applied multinomial logistic regression analysis to each class to explore predictive factors. We found that the overall slope of depressive symptoms in multicultural adolescents increased. Latent class analysis demonstrated three classes: (1) high-increasing class (i.e., high intercept, significantly increasing slope), (2) moderate-increasing class (i.e., moderate intercept, significantly increasing slope), and (3) low-stable class (i.e., low intercept, no significant slope). In particular, we found that the difference in the initial intercept of depressive symptoms determined the subsequent trajectory. There is a need for early screening for depressive symptoms in multicultural adolescents and preparing individual mental health care plans.

Height and body-mass index trajectories of school-aged children and adolescents from 1985 to 2019 in 200 countries and territories: a pooled analysis of 2181 population-based studies with 65 million participants

SummaryBackgroundComparable global data on health and nutrition of school-aged children and adolescents are scarce. We aimed to estimate age trajectories and time trends in mean height and mean body-mass index (BMI), which measures weight gain beyond what is expected from height gain, for school-aged children and adolescents.MethodsFor this pooled analysis, we used a database of cardiometabolic risk factors collated by the Non-Communicable Disease Risk Factor Collaboration. We applied a Bayesian hierarchical model to estimate trends from 1985 to 2019 in mean height and mean BMI in 1-year age groups for ages 5–19 years. The model allowed for non-linear changes over time in mean height and mean BMI and for non-linear changes with age of children and adolescents, including periods of rapid growth during adolescence.FindingsWe pooled data from 2181 population-based studies, with measurements of height and weight in 65 million participants in 200 countries and territories. In 2019, we estimated a difference of 20 cm or higher in mean height of 19-year-old adolescents between countries with the tallest populations (the Netherlands, Montenegro, Estonia, and Bosnia and Herzegovina for boys; and the Netherlands, Montenegro, Denmark, and Iceland for girls) and those with the shortest populations (Timor-Leste, Laos, Solomon Islands, and Papua New Guinea for boys; and Guatemala, Bangladesh, Nepal, and Timor-Leste for girls). In the same year, the difference between the highest mean BMI (in Pacific island countries, Kuwait, Bahrain, The Bahamas, Chile, the USA, and New Zealand for both boys and girls and in South Africa for girls) and lowest mean BMI (in India, Bangladesh, Timor-Leste, Ethiopia, and Chad for boys and girls; and in Japan and Romania for girls) was approximately 9–10 kg/m2. In some countries, children aged 5 years started with healthier height or BMI than the global median and, in some cases, as healthy as the best performing countries, but they became progressively less healthy compared with their comparators as they grew older by not growing as tall (eg, boys in Austria and Barbados, and girls in Belgium and Puerto Rico) or gaining too much weight for their height (eg, girls and boys in Kuwait, Bahrain, Fiji, Jamaica, and Mexico; and girls in South Africa and New Zealand). In other countries, growing children overtook the height of their comparators (eg, Latvia, Czech Republic, Morocco, and Iran) or curbed their weight gain (eg, Italy, France, and Croatia) in late childhood and adolescence. When changes in both height and BMI were considered, girls in South Korea, Vietnam, Saudi Arabia, Turkey, and some central Asian countries (eg, Armenia and Azerbaijan), and boys in central and western Europe (eg, Portugal, Denmark, Poland, and Montenegro) had the healthiest changes in anthropometric status over the past 3·5 decades because, compared with children and adolescents in other countries, they had a much larger gain in height than they did in BMI. The unhealthiest changes—gaining too little height, too much weight for their height compared with children in other countries, or both—occurred in many countries in sub-Saharan Africa, New Zealand, and the USA for boys and girls; in Malaysia and some Pacific island nations for boys; and in Mexico for girls.InterpretationThe height and BMI trajectories over age and time of school-aged children and adolescents are highly variable across countries, which indicates heterogeneous nutritional quality and lifelong health advantages and risks.FundingWellcome Trust, AstraZeneca Young Health Programme, EU.

Psychological suzhi and academic achievement in Chinese adolescents: A 2-year longitudinal study.

In the Chinese educational system, there has been an ongoing debate between using examination- or quality-oriented education. The Chinese concept of psychological suzhi was proposed based on quality-oriented education, and a positive link between psychological suzhi and academic achievement was found by cross-sectional studies; however, studies examining their longitudinal relationship are still lacking. To examine the longitudinal trajectories of Chinese adolescents' academic achievement and the longitudinal effects of psychological suzhi on academic achievement trajectories. Participants were 3,587 adolescents (Mage =14.85years, 51.1% male) in grades 7 and 10, from 10 secondary schools in southwest China. A 2-year (four-wave) longitudinal study was conducted, and growth mixture models were used to analyse the data. Four distinct developmental trajectories of academic achievement were identified (i.e., high-positive growth, middle-negative growth, low-stable, and lowest-stable) that were significantly predicted by different levels of psychological suzhi, particularly the dimension of cognitive quality. Cognitive quality was strongly associated with the initial academic achievement values in the high-positive growth group and linked to achievement rate (decreasing) in the middle-negative growth group. However, individuality quality and adaptability quality had a buffering effect on the rate of achievement decreasing in the middle-negative growth group. This study not only highlighted the promotive role of high cognitive quality on high levels of achievement (static) but also indicated the protective role of non-cognitive factors (i.e., individuality and adaptability) against a decreasing rate of academic achievement (dynamic).